Using a passive sensor array to determine the position of a signal source is a task that has long challenged researchers in many different fields of study. For this reason, there has also been a wealth of proposed solutions presented in the literature. However, due to the complexity of the problem, many of these techniques are only designed for application with sensor arrays of specific, highly symmetrical geometries.
In contrast to seismic sources, infrasonic sources can often be located near or even within the perimeter of the array. Additionally, their signals can often be damped by terrain or vegetation, making range estimation via signal amplitude inaccurate. For this reason, a time-delay based method was constructed in order to locate nearby sources of infrasound with arrays of any configuration. Even though this method was originally designed for use with infrasound, it can be applied equally well to any type of signal which can be detected by an array of sensors via an isotropic medium.